Cashew nut shell liquid (CNSL) is a renewable resource material, which is cheap and commercially available and is useful in various areas of chemical industry, such as plastics production. Technical grade CNSL comprises a major proportion (typically about 80% by wt) of a material sold commercially under the trade name CARDANOL which comprises a mixture of 3-(pentadec-8-enyl) phenol, 3-(pentadec-8, 11-dienyl) phenol, and 3-(pentadec-8,11,14-trienyl) phenol. Minor constituents include about 18% by wt. of a material also sold separately under the trade name CARDOL, which is a mixture of the corresponding 5-substituted resorcinols and about 2% by wt. of 2-methyl cardol, which is a mixture of corresponding 2-methyl-5-substituted resorcinols, and other materials.
The level of interest in developing new dibrominated phenoxy compounds is derived from the fact that these brominated compounds can be used as precursors of difunctional monomers or themselves as difunctional monomers and hence polymers. These compounds are useful as starting materials for the synthesis of a variety of 4,4′-disubstituted diphenyl ethers such as diiodides, diamines, dicarboxylic acids, diphenols, diboronic acids/diboronic esters etc. by employing known organic transformations. These 4,4′-disubstituted diphenyl ethers are useful condensation (difunctional) monomers for the production of high performance polymers employing metal-catalyzed polymerizations such as Suzuki polycondensation, Ni-catalysed polycondensation or Zn-catalysed polycondensation. They can also be polymerized using CO and various nucleophiles (e.g., diamines, diacylhydrazides, diphenols, aminophenols, etc) in the presence of palladium catalysts to yield the corresponding high-molecular-mass products.
It is well known in the prior art that incorporation of a long alkyl chain in polymer backbone imparts processability to the polymer. The improved properties they provide can benefit a wide range of applications, which seek better performance with improved processability. It is therefore of great interest and importance to synthesize new brominated phenoxy compounds with alkyl radical in their structure, more particularly from CNSL which is readily available commercially and is a renewable resource material.
There is no prior art available for the preparation of 1-bromo-4-(4′-bromophenoxy)-2-pentadecyl benzene and the inventors of the present invention are reporting the said compound and it's preparation using CNSL for the first time.